The present invention relates to thermal cutting torches and more particularly to a cutting torch of the consumable thermal torch type.
The thermal torch of the invention is typically employed for boring, cutting, and burning of hard-base material such as concrete, for example.
Such devices are typically fueled with oxygen gas which, for many years, has been used for piercing and cutting holes in hard base material such a concrete, slag, rock, and practically all ferrous metals. Such torches are comprised of an elongate all ferrous metal hollow pipe communicating at one end thereof with a source of oxygen which is caused to pass through the torch assembly. In operation, the thermic reaction of the cutting torch is initiated, with oxygen flowing therefrom, by exposing the outlet nozzle end of the torch to a preheated area whereupon ignition occurs. The thermic reaction then oxidizes the material to be treated with sufficient heat being produced to continue the cutting or piercing operation with the oxygen alone without any additional heat or flame required to facilitate the operation. The outlet nozzle end of the torch is maintained within a hole in the material being cut such that an oxygen stream emerges at the point of oxidation. The resultant heat is sufficient to actually burn the outermost distal end of the burner pipe so that as the operation proceeds, the torch assembly is consumed and must be replaced from time to time with a new length of burner pipe. Only a small portion of the oxygen consumed is required by the oxidation of the cutting torch itself, but it must be understood that the exothermic reaction of the burning torch greatly assists in supplying energy for the cutting operation.
It has been noted that the cutting action of such a cutting tooth structure could be increased by the employment of fusible rods disposed within the interior of the burner pipe. The resultant pipe and rod inserts provide additional fuel and greater energy output from the assembly. The insertion of the rods within the hollow interior portion of the burner pipe also manifestly decrease the area through which the oxygen fuel may travel so that the oxygen streams travel at greater velocity through the torch assembly. Among the problems created by such a structure is the increased erroding effect on the material being treated which increases splattering effect from and at the discharge of the torch and also the spreading of the cutting flame, so that the cutting action is not concentrated to achieve maximum cutting efficiency.
Most of the recent developments of this particular type of thermal cutting torch have been directed to the disposition of the centrally disposed rods and the various components for maintaining the rods in a desired configuration within the interior of the burner pipes, such as exemplified by U.S. Pat. Nos. 3,260,076; 3,460,223; 3,487,791; 3,507,230; 3,507,231; 3,507,419; 3,602,620; 3,738,288; 3,921,542; 4,050,680; 4,055,332; and 4,114,863.